Topology

24 Birthday Problems

As is tradition, the prize pool has increased (to $300 this year).

I have collapsed first and second place into a winner-takes-all arrangement (c’est la vie).

Furthermore, there are additional changes to the structure of this Game:

  1. you must now pass the problem set to be awarded the prize money;
  2. you may submit your solutions to the problem set at any point in the future;
  3. if you plagiarise work, I reserve the right to ban you from all subsequent competitions — grim trigger
  4. the problem and solution set will now be courteously supported by MathJaX, TikZ, and my own JavaScript
    • the problems can be found here, whilst the PDF can be found here and here (embedded).
    • my solutions will be available from the start of 2026; by viewing them you forfeit the prize money
  5. Good luck!

PDF

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Structure

Most notably, the structure from this year has changed. Instead of just offering a single PDF and then writing up solutions on this site, the problems themselves are accessible from below and once 2025 transpires, my solutions will be available as toggled nested environments.

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Functional Analysis

notes

these are some more informal notes that I have made after having taken the rigorous Analysis course.

  • \(c_{00}\) can be thought of as ‘finite vectors’. all \(\mathbb{R}^n\) tuples can be written as elements of \(c_{00}\) with infinitely many zeros after the $n$th term.
  • \(c_0\) are all sequences that converge to zero. thus they will include all those in \(c_{00}\) and more.
  • \(\ell^2\) are the vectors that fade fast enough for their energy 𐃏 to stay finite
  • \(\ell^\infty\) are the infinite vectors that never blow up – their entries are bounded.

\[c_{00} \subset c_0 \subset l^\infty \]

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Real Analysis

I am finding Real Analysis to be more difficult than any other mathematics that I have studied before. I can seem to verify the truth of statements because they seem right; but I am having a difficult time producing rigorous and correct proofs.

It seems that High-School children (on the internet) are able to self-study Fomin with success. Bitterly, we remind ourselves:

“Comparison is the thief of Joy”—Theodore Roosevelt (probably)

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